Troops loyal to socialist dictator Nicolás Maduro on Friday reportedly killed one and injured 12 members of a civilian group in Venezuela attempting to keep a checkpoint along country’s border with Brazil open for deliveries of U.S. humanitarian aid.

While Maduro is trying to prevent U.S. aid from entering Venezuela, Juan Guaidó, who the United States and other nations have recognized as the country’s rightful interim president, has vowed to personally bring in humanitarian assistance into the chaos-ridden country.

U.S. President Donald Trump’s pro-Guaidó administration denounced the attack.

“The United States condemns the killings, attacks, and the hundreds of arbitrary detentions that have taken place in Venezuela,” a State Department spokesperson told the Washington Post. “We stand with the victims’ families in demanding justice and accountability.”

Venezuelan troops killed a woman, 42-year-old Zorayda Rodriguez, marking the first fatality since Maduro ordered the closure of Venezuela’s land and air borders with neighboring countries, including Brazil, on Wednesday to prevent the entry of U.S. humanitarian aid into the country.

The Post reports:

At 6:30 a.m. on Friday, a military convoy approached a checkpoint set up by an indigenous community in the southern village of Kumarakapai, which rests on the main artery linking Venezuela to Brazil.

When the volunteers sought to block the military vehicles by standing in front of them, soldiers began firing assault rifles, wounding at least 12 people, four of them seriously.

George Bello, a spokesman for the indigenous community, told the Post, “The majority of the people support the entrance of humanitarian aid, and we want to keep our border open.”

Since Wednesday, Maduro troops have been preventing the entry of U.S. humanitarian aid into Venezuela from Brazil and other neighboring countries friendly to the United States.

This week, President Trump cautioned the Maduro against blocking aid from entering Venezuela, warning his military allies that they would eventually “lose everything” if they fail to renounce him.

“Today I have a message for every official who is keeping Maduro in place,” Trump proclaimed. “You cannot hide from the choice that now confronts you. You can choose to accept President Guaidó’s offer of amnesty and live your life in peace with your country. But you must not block humanitarian aid.”

“Or you can choose the second path; continuing to support Maduro,” the president continued. “You will find no safe harbor, no easy exit, no way out. You will lose everything.”